高孔率泡沫金属材料疲劳表征模型及其实验研究

通过基于高孔率开口泡沫金属材料结构特点的简化结构模型和受力状态分析,建立了此类材料在循环载荷作用下的负载结构-疲劳模型,分析得出了对应疲劳性能的衡量指标。在上述模型的基础上,运用由该模型得出的高孔率开口泡沫金属疲劳性能的衡量指标,以电沉积法所得泡沫镍为例,对此类材料的疲劳性能进行了相关的实验研究。通过压-压循环和弯曲循环两种载荷作用的实验,验证了理论分析所得疲劳性能衡量指标的可行性。结果表明:泡沫镍在压-压循环载荷作用下的类应力疲劳性能随孔率增大而降低,而在弯曲循环载荷作用下的类应变疲劳性能则随孔率增大和孔径减小而提高。

Fatigue Model for Foamed Metals with High Porosity and Corresponding Experimental Study

In the light of the simplified structural model of open-cell foamed metals with high porosity,the bearing structure-fatigue model was established for this type of materials under cyclic loading by force analysis,and the evaluating index was derived for the corresponding fatigue property.Based on the above mentioned model,the fatigue property of this type of materials was experimentally studied with the index from this model to evaluate the fatigue property of the nickel foam with open-cell structure.Using two sorts of loading experiments of pressing-pressing and bending cycles,the obtained index weighing the fatigue property was validated to be feasible.The results show that the similar stress fatigue property decreases when the porosity increases for the nickel foam under loading cycle of pressing-pressing,but the similar strain fatigue property is improved when the porosity increases and the pore diameter decreases for this experimental material under cyclic bending loading.